Popular Mechanics (South Africa)
THE DISASTER-PROOF INTERNET
The earthquake in Iran, Hurricane Irma in Puerto Rico, California wildfires. As vital as food and clean water, catastrophe response means getting aid workers and civilians back online. But could the tools used to create emergency internet be used to conne
SATELLITES HOW IT WORKS
Instead of travelling through towers, which are antennas connected to fibre-optic cables in the ground, data comes from low-earth-orbit satellites that are calibrated to rotate with Earth and hold position above the region they serve. Right now companies such as Hughesnet and Exede use the technology to sell internet to people who live beyond MTN or Vodacom’s reach. Other than the dishes and hardware you need on the ground, the satellites themselves are impervious to terrestrial disasters. The main drawback is signal attenuation. When a transmission has to go from that high up all the way down to Earth, it loses data along the way and has to resend the signal until everything reaches the recipient. So data transfer is slow. Assuming no rain or even clouds are blocking it, the connection feels like using a 56K modem. That’s good for an airport or hospital that needs to communicate and run basic software but unsuitable for things like video streaming and large-file transfer.
VERDICT
Satellites are extremely expensive to launch, so it’ll be a while before they replace, or even supplement, towers. “There’s a lot that can be done with caching and buffering, using machine learning to plan what needs to be stored on what servers,” says Kerri Cahoy, an associate professor at MIT and NASA researcher who specialises in spacecraft communications and satellites. “It’s possible to do better.”
HOW IT WORKS
Devices such as the Airbus Zephyr, Facebook’s Aquila drone, and the Project Loon balloons use solar panels to power antennas and computers that amplify the signal from functioning terrestrial cell towers. Compared to the labour, time and civil engineering required to build a new cell tower, something like Project Loon is cheap to deploy. Once launched, a balloon basically flies itself, providing LTE to nearly 5 000 square kilometres. But even Project Loon’s record for staying in the air is relatively short: 190 days – not as reliable as a cell tower or fibre cables. Connecting a rural area requires a consistent connection, and sometimes-on internet won’t cut it for paying customers. That points to a larger issue with getting internet to remote places. “The way these towers work is: are there enough users to pay it off?” says Sal Candido, the head software engineer for Project Loon. “The carriers have to get a return on their investment.”
VERDICT
Brilliant advancement for disasters, not reliable enough to replace cell towers. Yet.
ROOFTOP DIY HOW IT WORKS
Off-the-shelf routers and antennas set high on rooftops work like small cell towers but with a much shorter range. Organisations like the Detroit Community Technology Project in Detroit or the Red Hook Initiative in New York City use the devices and their bandwidth or satellite connection to build their own networks. This can give internet access to people who can’t afford home Wi-fi or a phone data plan or, in emergency response, provide internet service while you wait for the service provider to repair cell towers. Unlike cell towers, however, these networks can’t handle many people. After Hurricane Sandy hit New York City in 2012, the Red Hook Initiative’s network could provide internet to only 150 users at once.
VERDICT
A reliable, if limited, alternative to airborne internet. We also applaud any homemade project like this.
FLYING ANTENNAS